1. Field
The present disclosure relates to inter-layer video encoding and decoding methods. In more detail, the present disclosure relates to a method of compensating for an illumination difference between inter-layer images.
2. Related Art
As hardware for reproducing and storing high resolution or high quality video content is being developed and supplied, a need for a video codec for effectively encoding or decoding the high resolution or high quality video content is increasing. According to a video codec of the related art, a video is encoded according to a limited encoding method based on a macroblock having a predetermined size.
Image data of a spatial domain is transformed into coefficients of a frequency domain via frequency transformation. According to a video codec, an image is split into blocks of predetermined size, discrete cosine transformation (DCT) is performed on each block, and frequency coefficients are encoded in block units, for rapid calculation of frequency transformation. Compared with image data of a spatial domain, coefficients of a frequency domain are easily compressed. In particular, since an image pixel value of a spatial domain is expressed according to a prediction error via inter prediction or intra prediction of a video codec, when frequency transformation is performed on the prediction error, a large amount of data may be transformed to 0. According to a video codec, an amount of data may be reduced by replacing data that is consecutively and repeatedly generated with small-sized data.
With the demand for video captured with various image qualities or captured at multiple views, a transmission amount of video data that corresponds to the number of image quality levels or the number of views can be a problem. Thus, much effort is being continuously made to efficiently encode and decode a multiview video and to decrease a transmission data amount.
A multilayer video codec encodes and decodes a first layer video and one or more second layer videos. By removing temporal/spatial redundancy of the first layer video and the second layer video, and redundancy between layers, amounts of data of the first layer video and the second layer video may be reduced.